Commercial Flights Are Experiencing ‘Unthinkable’ GPS Attacks and Nobody Knows What to Do::New “spoofing” attacks resulting in total navigation failure have been occurring above the Middle East for months, which is “highly significant” for airline safety.
Pretty sure this is the story, rings true to my memory of the company name starting with “L”: https://arstechnica.com/tech-policy/2011/04/lightsquared-broadband-a-threat-to-gps/
Although this article doesn’t cover how the GPS systems used cheap filtering circuits that didn’t adequately filter out adjacent frequencies. This was done purely to save money, because there wasn’t anything using the adjacent frequencies. As a result, LightSquared went bankrupt in 2012.